Maintaining your vehicle’s transmission is essential to ensuring smooth operation and long-term reliability. Among the many maintenance tasks, checking and maintaining proper transmission fluid levels is one of the most critical steps for preventing costly repairs. The 2018 Toyota Corolla is known for its reliability and fuel efficiency, but like any vehicle, it requires attention to detail when it comes to fluid checks and maintenance.
In this detailed guide, we’ll walk you through the process of how to check the transmission fluid in a 2018 Toyota Corolla, whether it’s equipped with a manual or automatic transmission. We’ll also explain why maintaining proper fluid levels is crucial, the symptoms of low or dirty transmission fluid, and common mistakes to avoid. By the end of this article, you’ll be well-equipped to inspect your Corolla’s transmission system and maintain optimal performance.
Understanding the Transmission System in the 2018 Toyota Corolla
Before diving into the process, it’s important to understand the basics of the Corolla’s transmission. The 2018 model offers two transmission options:
- Automatic transmission – a continuously variable transmission (CVT) for improved fuel economy and smooth acceleration.
- Manual transmission – a 6-speed manual for those who prefer a hands-on driving experience.
Because the CVT transmission differs from a traditional automatic transmission, the process of checking transmission fluid varies slightly. In many modern vehicles like the 2018 Corolla, especially those with CVT, transmission fluid is considered a “lifetime” fluid, meaning Toyota does not recommend routine changes under normal driving conditions. However, checking the fluid level and condition is still advised, especially if you’re experiencing performance issues.
Why Checking Transmission Fluid Matters
Checking your transmission fluid regularly can prevent serious mechanical failures and costly repairs down the road. Transmission fluid serves multiple critical functions, including:
- Reducing friction and wear by lubricating internal components.
- Removing heat from the transmission, preventing overheating.
- Providing hydraulic pressure for gear shifts in automatic transmissions.
- Maintaining internal cleanliness with additives that fight sludge and debris.
Low or degraded fluid can lead to gear-shifting problems, overheating, and transmission failure. Regularly inspecting your transmission fluid allows you to detect issues early and maintain smooth operation.
Consequences of Neglecting Transmission Fluid Maintenance
Ignoring transmission fluid health can result in:
- Slipping gears – Caused by low or old fluid, which reduces hydraulic pressure needed for smooth gear changes.
- Overheating transmission – Without sufficient fluid, the transmission can overheat, potentially leading to a breakdown.
- Increased wear and damage – Lack of lubrication can cause gears and other components to wear prematurely.
Tools and Supplies Needed for the Job
Before beginning, gather the following items:
| Item | Purpose |
|---|---|
| Owner’s Manual | Provides specific instructions and fluid type recommendations |
| Clean cloth or paper towel | To wipe the dipstick and check fluid cleanliness |
| Funnel | Used to refill fluid through proper channels |
| Gloves | Protects against hot fluid and clean hands |
| Nitrile gloves | Durable and safe for working with automotive fluids |
| Rubber gloves | Alternative option |
| Flashlight | For better visibility under the hood |
| Jack and Jack Stands (optional, depending on model) | Necessary only if undercarriage inspection required |
Checking Transmission Fluid in a 2018 Toyota Corolla with CVT
Unlike traditional automatic transmissions, the 2018 Corolla with CVT does not have a dipstick for checking transmission fluid easily. Instead, the process must be performed using specialized procedures to ensure accurate readings.
Preparing Your Vehicle
To get accurate results when checking CVT fluid levels:
- Warm up the engine – Drive the car for at least 10–15 minutes to bring the fluid to operating temperature (between 50°C to 80°C or 122°F to 176°F).
- Park on a level surface – This helps ensure an accurate reading.
- Turn on the air conditioning – This places a light load on the engine and allows the ECU to better detect performance under typical conditions.
Procedure to Check Transmission Fluid Level
Follow these steps for checking your Corolla’s CVT transmission fluid:
- Connect an OBD-II scanner – To activate the temperature reading mode for diagnostics (this may also alert you to error codes).
- Locate the transmission fluid inspection hole – This is on the underside of the transmission. Consult your owner’s manual or service guide for precise location.
- Raise the vehicle safely using a jack and jack stands – Ensure proper support before placing hands near moving components.
- Remove the inspection plug or check bolt – Fluid should begin to trickle out.
- Assess the fluid level – If no fluid comes out, the level is low and will need to be topped off using pressurized filling equipment.
Note: Due to the complexity of the CVT system, it is often recommended to visit a certified Toyota service center for this procedure unless you’re experienced with automotive mechanics.
Checking Transmission Fluid in a 2018 Toyota Corolla with Manual Transmission
Checking the transmission fluid in a manual Corolla is more straightforward, as it does include a dipstick for fluid inspection. However, some models may vary slightly, so always reference the owner’s manual for specific guidance.
Step-by-Step Guide for Manual Transmission Fluid Inspection
- Warm up the engine – Run for a few minutes to allow fluid to expand and provide a more accurate reading.
- Park on level ground and set the emergency brake – Ensures vehicle stability and measurement accuracy.
- Open the hood – Locate the transmission fluid dipstick near the back of the engine compartment.
- Pull out the dipstick and wipe clean with a cloth – Observe the markings for full and low levels.
- Reinsert and remove the dipstick – Check the fluid level relative to the markings.
- Inspect color and odor – Fresh transmission fluid is typically a clear red color. If it appears dark, smells burnt, or contains visible debris, consider a transmission fluid replacement.
What to Do If Your Transmission Fluid Is Low or Dirty
If your inspection reveals that the fluid level is low or the condition is poor, here are your options:
Adding Transmission Fluid
If the fluid is low but still in good condition:
- Use the correct fluid type – For 2018 Toyota Corolla models, Toyota CVT Fluid TC or Toyota Genuine Motor Oil for manuals.
- Add fluid slowly – Use a funnel to avoid spills, and add in increments to prevent overfilling.
- Recheck the level – After refilling, reinsert the dipstick and check again to ensure proper levels.
Changing Transmission Fluid (When Necessary)
If the fluid appears dark or burnt:
- Drain the fluid – This often requires removing the transmission pan (manual) or using a specialized machine (CVT).
- Clean or replace transmission filter – Especially important for manual transmissions; CVT systems may not allow standard filter changes.
- Refill with the correct fluid – Again, using Toyota-recommended fluid ensures compatibility and performance longevity.
Caution: Improper fluid changes on CVT systems can cause extensive damage. If you’re unsure, seek help from a Toyota-certified mechanic.
Symptoms of Transmission Problems in the 2018 Corolla
Recognizing early signs of transmission trouble can save you time and money:
- Difficulty shifting gears – Especially noticeable in manual transmissions.
- Delayed or rough shifting – In automatic (CVT) models, this can signal a hydraulic pressure issue.
- Unusual noises (whining, humming) – Often an indicator of bearing or gear damage.
- Transmission warning light – Illuminates if the system detects a fault or overheating condition.
- Slipping gears – Caused by insufficient hydraulic pressure or worn components.
- Leaking fluid – Visible puddles under the car after parking may point to a seal or pan leak.
If you experience any of these symptoms, checking the transmission fluid should be one of your first lines of action.
Common Mistakes to Avoid When Checking Transmission Fluid
Even experienced DIY mechanics can make mistakes when handling transmission fluid. Here are several key errors to avoid:
- Checking cold fluid – Fluid expands when hot, leading to inaccurate readings if checked cold.
- Misidentifying dipsticks – The Corolla may have two similar-looking dipsticks (one for oil and one for transmission). Ensure you verify which is which.
- Overfilling the transmission – Excess fluid leads to foaming, which can damage internal components.
- Using the wrong fluid – The CVT design requires specific fluid types. Using the incorrect type can void warranties and damage components.
- Rushing the process – Take your time to ensure accurate inspection and maintenance.
Why Checking the Fluid Matters Even in ‘Lifetime’ Systems
Even if your transmission fluid is labeled “lifetime,” it can degrade over time due to heat, moisture, and wear. Toyota recommends inspecting your CVT fluid at major service intervals or if you notice performance issues. Regular visual checks, even once a year, can provide valuable insight into the health of your vehicle’s most important mechanical systems.
Tips for Maintaining the Transmission System of Your 2018 Toyota Corolla
Proper care of your Corolla’s transmission involves more than just checking fluid levels. Here are additional tips to extend the life of your transmission:
- Follow the manufacturer’s maintenance schedule – Toyota includes recommended transmission service intervals in the owner’s manual.
- Avoid aggressive driving – Quick acceleration and hard braking put extra stress on your transmission system.
- Warm up the engine before driving – Especially important in cold climates to ensure proper fluid flow.
- Use the brake when shifting – Always come to a complete stop before shifting from drive to reverse and vice versa.
- Check for recalls or technical service bulletins (TSBs) – Some Corolla models underwent CVT updates, and your vehicle may qualify for a transmission-related repair program.
When to Visit a Toyota Service Center for Transmission Issues
While many basic maintenance tasks can be performed DIY, there are instances when professional assistance is crucial:
- Dealing with CVT-specific procedures – Requires specialized tools and technical knowledge.
- Transmission warning light is on – May indicate internal faults requiring diagnostic scan tools.
- Need for fluid changes involving the CVT system – Attempting a DIY fluid change on a CVT without proper tools can cause damage.
- Unusual symptoms persist even after rechecking fluid – May require disassembly, diagnostics, and major repairs.
Toyota certified technicians are trained specifically in diagnosing and repairing Corolla transmissions, including complicated CVT systems.
Conclusion: Keep Your 2018 Toyota Corolla Running Smoothly with Proper Maintenance
Regularly checking your 2018 Toyota Corolla’s transmission fluid is a simple but powerful maintenance task that can significantly affect the vehicle’s performance and longevity. Whether you drive a CVT-equipped automatic or a manual model, knowing how to inspect and maintain optimal transmission fluid levels ensures smooth shifting, increased fuel efficiency, and fewer expensive repairs in the future.
While the process for checking transmission fluid in a CVT vehicle is more complex than in traditional units, taking the time to consult professional guidance or the owner’s manual can ensure that your vehicle remains in peak condition for years to come. By staying proactive with maintenance, you’re not only protecting your investment but also enhancing your driving experience in one of Toyota’s most popular compact cars — the 2018 Corolla.
Remember: Knowledge and routine care are the best ways to keep your Corolla on the road, reliably and efficiently.
Why is checking transmission fluid important in a 2018 Toyota Corolla?
Checking the transmission fluid in your 2018 Toyota Corolla is essential for maintaining the health and performance of your vehicle’s transmission system. Transmission fluid lubricates the internal components of the transmission, helps regulate temperature, and ensures smooth gear shifts. Over time, transmission fluid can break down or become contaminated, which can lead to increased wear and even transmission failure.
Regularly inspecting the fluid’s level and condition helps catch potential issues early, such as leaks or fluid degradation. A simple check can prevent costly repairs and extend the life of your vehicle. For the 2018 Toyota Corolla, which uses a continuously variable transmission (CVT) in many models, maintaining proper fluid levels and cleanliness is particularly crucial due to the CVT’s sensitivity to heat and wear.
Can I check the transmission fluid in my 2018 Toyota Corolla myself?
Yes, you can check the transmission fluid in your 2018 Toyota Corolla at home with basic tools and a little time. Unlike some newer vehicles that don’t have a traditional dipstick, the 2018 Corolla allows access for a manual check. This gives owners the opportunity to monitor their transmission fluid without needing to go to a mechanic for a basic inspection.
However, it’s important to understand that the Corolla’s CVT transmission requires specific fluid (Toyota WS), and the process is different than for vehicles with a standard automatic transmission. Following the correct procedure and checking when the engine is at the proper operating temperature will ensure accurate results. If you’re unsure or uncomfortable during any part of the process, it’s best to consult a professional technician.
When should I check the transmission fluid in my 2018 Toyota Corolla?
You should check the transmission fluid in your 2018 Toyota Corolla when the vehicle is running and has reached normal operating temperature. This means you should drive the car for about 15 to 20 minutes to warm up the fluid, allowing it to expand and give an accurate reading. Checking the fluid when it’s cold can lead to a false low-level reading and unnecessary topping off.
Toyota recommends checking the transmission fluid every 30,000 to 60,000 miles, depending on your driving habits and conditions. If you frequently drive in stop-and-go traffic, tow heavy loads, or drive in extreme temperatures, you may want to inspect the fluid more frequently. Early detection of issues such as low levels or discolored fluid can lead to timely maintenance, protecting your transmission over time.
How do I check the transmission fluid level in a 2018 Toyota Corolla?
To check the transmission fluid level, park your 2018 Toyota Corolla on a level surface and start the engine. Shift through all the gears, and then return to Park. Locate the transmission fluid dipstick under the hood—on the Corolla, it’s typically labeled with a red or orange handle. Pull it out, wipe it clean, reinsert it fully, and then remove it again to check the fluid level.
The fluid should be between the two marks labeled “HOT” on the dipstick. If it’s below the lower mark, you’ll need to add more fluid. Use a long-neck funnel or a fluid pump to slowly add the recommended Toyota WS transmission fluid. Recheck the level after adding, and remember to avoid overfilling as this can cause foaming and erratic behavior in your CVT system.
What should the color and consistency of the transmission fluid indicate?
Healthy transmission fluid in a 2018 Toyota Corolla should be bright red or pink in color and have a slightly sweet smell. This indicates the fluid is clean and effective at lubricating and cooling the transmission components. If the fluid appears translucent and just slightly darker than new fluid, it’s still in good condition.
However, if the fluid is brown or black, smells burnt, or has particles or debris in it, this is a sign of degradation or internal wear. These issues can lead to poor transmission performance and may require a professional inspection or fluid change. Always note the color and smell when checking the fluid—it can provide valuable insights into the overall health of your CVT transmission.
Where do I add transmission fluid in the 2018 Toyota Corolla?
In the 2018 Toyota Corolla, transmission fluid is added through the dipstick tube. You’ll need a funnel or a long-necked transmission fluid pump to reach down into the tube and add fluid slowly. Be careful not to spill or overfill, as overfilling can cause serious transmission issues, especially in vehicles with a continuously variable transmission (CVT), which are sensitive to fluid levels.
It’s important to use the correct type of fluid—Toyota recommends Genuine Toyota WS (World Standard) transmission fluid for this model. You can purchase this fluid at most auto parts stores or at a Toyota dealership. If you’re unsure how much fluid to add or if your level is well below normal, it’s best to consult a certified mechanic to avoid potential damage or costly repairs.
What are the signs of low or bad transmission fluid in a 2018 Toyota Corolla?
Symptoms of low or degraded transmission fluid in the 2018 Toyota Corolla may include difficulty shifting gears, delayed acceleration, jerky or rough transitions, or a noticeable slipping sensation while driving. You may also experience transmission overheating, which the vehicle might indicate with warning lights such as the Check Engine light or a transmission temperature warning.
Unusual noises like whining or humming, especially when changing gears, can also signal a problem. Additionally, if you notice a leak—evidenced by red or brown fluid under the vehicle—it’s important to address it quickly. These signs indicate that the transmission is not receiving proper lubrication and cooling, which can cause serious damage to the CVT if not corrected promptly through fluid inspection and maintenance.